Developing with ArcGIS Raster APIs. Hong Xu, Qian Liu and Peng Gao

Transcription

1 Developing with ArcGIS Raster APIs Hong Xu, Qian Liu and Peng Gao

2 Presentation Outline Introduction of raster data model Access and display of raster data Operations on raster data SaveAs,filtering,transformation,mosaic etc. Creating raster data and writing pixels Raster attribute table Loading raster to a geodatabase

3 Characteristics of Raster Data pixel size pixel value pixel type columns rows bands Stored in many formats GRID, TIFF, IMG, JPEG, JP2000, etc. ArcSDE,, PGDB FGDB PCI, ECW, USGS ASCII DEM, BSB, PCRaster,, HDF4 Pyramids Statistics Colormap Raster attribute table Spatial reference Geodata transformation

4 Common APIs for Raster Data Access Same interface to access data in all supported formats. Auxiliary file (aux) to store information that are not handled by formats.rrd file is to store pyramids Geodatabase raster data support those properties internally Open structure for adding new raster format support GDAL driver Format dll

5 Raster Data Model Raster datasets (RasterDataset) Arrays of pixels and the associated information stored in a file system or geodatabase. Raster catalogs(rastercatalog) A collection of raster datasets RasterDataset RasterCatalog

6 Raster Data Objects Workspace RasterCatalog * RasterDataset Selection DefinitionQuery Raster GdbRasterCatalog Layer RasterLayer RasterRender PixelFilter PixelBlock MosaicRaster Raster GeometryProc GeodataXForm

7 Presentation Outline Introduction of raster data model Access and display of raster data Operations on raster data SaveAs,filtering,transformation,mosaic etc. Raster attribute table Creating raster data and writing pixels Loading raster to a geodatabase

8 Open Raster Data IRasterWorkspaceEx (optional) IRasterWorkspace2 (optional) Workspace OpenRasterCatalog (Name):IRasterCatalog OpenRasterDataset (Name):IRasterDataset OpenRasterDataset (Name): IRasterDataset. Access GDB raster dataset and raster catalog IRasterWorkspaceEx workspace; IWorkspaceFactory workspacefactory = new FileGDBWorkspaceFactoryClass(); workspace = (IRasterWorkspaceEx) workspacefactory. Factory.OpenFromFile(@"c: (@"c:\temp\data.gdb", 0); IRasterDataset raster terdataset = workspace.openrasterdataset OpenRasterDataset("airphoto"); IRasterCatalog raster tercatalog = workspace.openrastercatalog OpenRasterCatalog("DRGs"); Access raster dataset from file system IRasterWorkspace workspace; IWorkspaceFactory workspacefactory = new RasterWorkspaceFactoryClass (); workspace = (IRasterWorkspace) workspacefactory.openfromfile(@"c: actory.openfromfile(@"c:\temp", temp", 0); IRasterDataset raster terdataset = workspace.openrasterdataset OpenRasterDataset("redlands.tif");

9 Raster Dataset Display IRasterLayer RasterLayer CreateFromDataset (RasterDataset):IRasterLayer CreateFromRaster(Raster): IRasterLayer Renderer:IRenderer Set a raster renderer or use the default IRasterLayer rasterlayer = new RasterLayerClass(); rasterlayer.createfromdataset rasterdataset; rasterlayer.renderer = renderer; mapcontrol.focusmap.addlayer rasterlayer Raster Renderers: RGB renderer,, Stretch renderer,unique value renderer,classify renderer, Colormap renderer Use RasterRendererMakerDefault to custom your own default rendering behavior

10 Raster Catalog Display IRasterLayer GdbRasterCatalogLayer Setup (Table as ITable): IGdbRasterCatalogLayer Renderers : IArray Set available renderers or use default IGdbRasterCatalogLayer cataloglayer = new GdbRasterCatalogLayerClass(); cataloglayer.setup Setup(RasterCatalog); cataloglayer.renderers = RendererArray; mapcontrol.focusmap.addlayer cataloglayer; RasterCatalogRendererPickerDefault to customize default renderer picker RasterCatalogLayer is for displaying a 8.x table based raster catalog.

11 Presentation Outline Introduction of raster data model Access and display of raster data Operations on raster data SaveAs,filtering,transformation,mosaic etc. Creating raster data and writing pixels Raster attribute table Loading raster to a geodatabase

12 Raster Setting Raster Properties IRasterProps ISaveAs Raster Extent: IEnvelope Height:Long NoDataValue:Variant PixelType:RstPixelType SpatialReference: ISpatialReference Width: Long MeanCellSize:IPnt SaveAs (Name as String, ws as IWorkspace,format as String) IRasterDataset.CreateDefaultRaster creates Raster Set Extent, column/row Width of extent = cell size x #column Cell size is derived Persist using SaveAs

13 Raster - SaveAs ISaveAs ISaveAs2 Raster or RasterDataset SaveAs (Name, workspace, Format): IRasterDataset SaveAsRasterDataset (Name, workspace, Format, StorageDef) IRasterDataset ISaveAs is supported by both Raster and RasterDataset Mainly perform format conversion for RasterDataset case Resampled and persist the change if used with Raster Support SaveAs to GRID, IMAGINE, TIFF and geodatabases and more in FGDB JPEG, JP2, PNG, BMP, PCI, DEM, PCRaster,, HDF4 Set compressions using RasterStorageDef Control pyramids building when saveas to GRID, IMG and TIFF

14 Raster Pixel vs. Map Space column IRaster2 Raster MapToPixel (x, y, column, row) PixelToMap (column, row, x, y) GetPixelValue(Band, Column, Row) Y row x Given (x,y) in map, find column and row as well as the pixel value IRaster2 raster = (IRaster2)rasterDataset.CreateDefaultRaster; int icolumn = raster.topixelcolumn ToPixelColumn(mapX); int irow = raster.topixelrow (mapy); double value = raster.getpixelvalue GetPixelValue(0, icolumn, irow); At 9.1 IRasterGeometryProc2::WKSPointsMap2PixelTransform IPixelBlock::GetVal

15 New Geodata Transformations IGeodataXform IClone IPersist IPersistStream GeodataXform IGeodataXform : IUnknown Domains: IGeometryCollection IsIdentity: Boolean SpatialReference: ISpatialReference Transform (in Direction: esritransformdirection, in npoints: Long, in points: WKSPoint) TransformCellsize (in Direction: esritransformdirection, in dx: Double, in dy: Double, in pareaofinterest: IEnvelope) RPCXform AdjustXform PolynomialXform CoordinateXform CustomXform TransformExtent (in Direction: esritransformdirection, in pextent: IEnvelope) TransformPoints (in Direction: esritransformdirection, in ppoints: IPointCollection) SplineXform Support polynomial (RasterGeometryProc( in 9.1), Spline, rubbersheeting transformations Raster re-projection Image orthorectification Create your own Xform class

16 Performing Transformations RasterDataset IGeoDatasetSchemaEdit2 AlterGeodataXform (IGeodataXform xform) GeodataXform Raster IRaster2 : IUnknown GeodataXform: IGeodataXform GeoTransformations: IGeoTransformationOperationSet RasterDataset: IRasterDataset RasterXformer: IRasterXformer Persist with dataset using IGeoDataSchemaEdit2 Auxiliary file based raster, internal for GDB raster Apply to a Raster using IRaster2::GeodataXform Transform extent, the set Transform cell size, then set width/height SaveAs Project raster with datum transformation IRaster2::GeoTransformations

17 Pixel Filters PixelFilter IPixelFilter : IUnknown Filter (in pblock: IPixelBlock) Raster IPixelOperrtion : IUnknown Filter Pansharpening Filter RasterConvolution Filter RemapFilter CustomFilter ConvolutionFilter 3x3, 5x5 low pass, high pass, and etc. Define your own kernel (PutCoefficients( PutCoefficients) PanSharpeningFilter Mean, Brovey,, IHS, and ESRI methods Create your own PixelFilter class Apply to Raster using IPixelOperation::Filter

18 Mosaicking Raster Data IRasterCollection IMosaicRaster ISaveAs IMosaicRaster2 MosaicRaster Append (IRaster:raster) RasterCatalog (IRasterCatalog rastercatalog) WhereClause (String whereclause) MosaicColormapMode RasterCatalogTable (IRasterCatalogTable catalogtable) Using MosaicRaster to create new dataset Mosaic from many raster datasets Mosaic from RasterCatalog & WhereClause Mosaic from RasterCatalogTable ISaveAs Mosaic to an existing dataset (appending) IRasterDatasetEdit::Mosaic RasterLoader Designed for mosaicking SDE/FGDB raster dataset

19 Presentation Outline Introduction of raster data model Access and visualization of raster data Operations on raster data SaveAs,filtering,transformation, mosaic etc. Creating raster data and writing pixels Raster attribute table Loading raster to a geodatabase

20 Creating Raster Dataset IRasterWorkspaceEx (optional) IRasterWorkspace2 (optional) Workspace CreateRasterCatalog (Name, Fields, ShapeName, RasterName, Configkey):IRasterCatalog CreateRasterDataset (Name, #Band, PixelType, StorageDef, ConfigKey, RasterDef, GeometryDef):IRasterDataset CreateRasterDataset (Name, Format, origin, column, row, cellx, celly, #Band, PixelType, spatialreference, perment ): IRasterDataset. Create file raster dataset With dimension Populated with default values Create GDB raster dataset Empty raster Mosaic or write using pixel blocks Create in-memory raster dataset Stores the pixels in memory

21 Working with PixelBlocks IRaster Raster CreatePixelBlock(size):IPixelBlock PixelBlock IPixelBlock3 PixelData(#band) IRaster raster = rasterdataset.createdefaultraster; IRasterProps rasterprops = (IRasterProps)raster; rasterprops.extent = extent; rasterprops.width = 512; rasterprops.height = 512; IPixelBlock3 pixelblock= (IPixelBlock3)raster.CreatePixelBlock CreatePixelBlock(blockSize); System.Array pixelarray = (System.Array)pixelblock.get_PixelData get_pixeldata(0); //edit pixel values pixelblock.set_pixeldata set_pixeldata(0, pixelarray); IRasterEdit rasteredit = (IRasterEdit)raster( IRasterEdit)raster; rasteredit.write (tlcorner, pixelblock);

22 Using PixelBlock with RasterCursor IRaster IRaster2 Raster CreateCursor(): IRasterCursor CreateCursorEx(Ipnt: Size) :IRasterCursor RasterCursor IRasterCursor PixelBlock: IPixelBlock Next TopLeft: IPnt Reset PixelBlock IRaster2 raster2 = (IRaster2 ) raster; IRasterEdit rasteredit = (IRasterEdit)raster; IRasterCursor cursor = raster2.createcursorex CreateCursorEx(blockSize); IPixelBlock3 pixelblock; IPnt tlcorner; do { pixelblock = (IPixelBlock3)cursor.PixelBlock PixelBlock; //do something with the pixel block tlcorner = cursor.topleft TopLeft; rasteredit.write Write(tlCorner, pixelblock); } While (cursor.( cursor.next == true)

23 Presentation Outline Introduction of raster data model Access and display of raster data Operations on raster data Conversion,mosaic,transformation etc. Creating raster data and writing pixels Raster attribute table Loading raster to a geodatabase

24 Raster Attribute Table Raster of all formats support raster attribute table RAT for SDE/FGDB raster is stored as a table with a special name and joined internally GRID still uses VAT.dbf format for other file raster formats Build raster attribute table Single band of integer type Build attribute table if not exists (65563) IRasterDatasetEdit2 rasterdatasetedit = (IRasterDatasetEdit2)rasterDataset; rasterdatasetedit2.buildattributetable

25 Raster Attribute Table Access raster attribute table IRasterBandCollection bandcol = rasterdataset; IRasterBand rasterband = bandcol.item(0); ITable rastertable = rasterband.attributetable AttributeTable; IRaster2 raster = rasterdataset.createdefaultraster CreateDefaultRaster; rastertable = raster.attributetable AttributeTable; Raster table is a generic table (ITable( ITable) ) in and supports editing Add a field Modify a value in the table

26 Presentation Outline Introduction of raster data model Access and display of raster data Operations on raster data SaveAs,filtering,transformation, mosaic etc. Raster attribute table Creating raster data and writing pixels Loading rasters to a geodatabase

27 Create Large Raster Mosaic Create an empty raster dataset Set pyramid reference point Define spatial reference Specify pyramid level and resample method Specify storage parameter Tile size, compression type and quality IRasterStorageDef rasterstoragedef; //set pyramid origin IPoint origin = new PointClass(); origin.putcoords(-180, 90); rasterstoragedef.origin = origin; //set compression to JPEG 25 rasterstoragedef.compressiontype = esrirastercompressiontype.esrirastercompressionjpeg; rasterstoragedef.compressionquality = 25; //set spatial reference to GCS_WGS_1984 ISpatialReference spatialreference = CreateSpatialReference(4326); rasterdef.spatialreference = spatialreference;

28 Mosaic To Large Raster Mosaic Mosaic raster dataset Resolve overlapping area Process background Shift/resample if cells are not aligned void MosaicRaster(IRasterDataset dataset, IRasterDataset input) { IRasterLoader rasterloader = new RasterLoaderClass(); //set background to ignore rasterloader.background = 0; //set tolerance so that it shifts if there is a cell misalignment rasterloader.pixelalignmenttolerance = ; } //mosaic rasterloader.load(dataset, input.createdefaultraster());

29 Raster Catalog IRasterCatalog IFeatureClass... RasterCatalog GeometryDef RasterDef IRasterCatalogItem IRow IRowBuffer... RasterCatalogItem RasterStorageDef RasterValue RasterDef defines properties for Raster column Spatial reference, managed or unmanaged raster values can persist its own spatial reference GeometryDef defines spatial reference for Geometry field RasterStorageDef is used to set storage properties Compression, pyramid building, pyramid origin, tile size, etc.

30 Create Raster Catalog Specify raster column and geometry column properties when creating fields IRasterDef Spatial reference, management type IGeometryDef Spatial reference, spatial index grids //raster field IField2 field2 = new FieldClass(); IFieldEdit2 field2edit = (IFieldEdit2)field2; IRasterDef rasterdef = new RasterDefClass(); //shape field IGeometryDef geometrydef = new GeometryDefClass(); IGeometryDefEdit geometrydefedit = (IGeometryDefEdit)geometryDef; geometrydefedit.spatialreference_2 = spatialreference; // set other properties fieldedit.name_2 = "SHAPE"; fieldedit.type_2 = esrifieldtype.esrifieldtypegeometry; fieldedit.geometrydef_2 = geometrydef; field2edit.type_2 = esrifieldtype.esrifieldtyperaster; field2edit.name_2 = "RASTER"; rasterdef.spatialreference =CreateSpatialReference(29714); field2edit.rasterdef = rasterdef; field2edit.ismanaged = true;

31 Load Raster Dataset To Raster Catalog Batch loading Load a directory or a list of raster datasets Control projection on-the the-fly Control geotransformation Specify storage parameters for all the rasters IRasterCatalogLoader catalogloader = new RasterCatalogLoaderClass(); //set workspace where raster catalog resides catalogloader.workspace = workspace; //maintain spatial reference of the input raster catalogloader.projected = false; //set storage parameter catalogloader.storagedef = storagedef; //load catalogloader.load Load(catalogName, folder, null);

32 Load Raster Dataset To Raster Catalog Individual loading Is similar to inserting feature to a featureclass Create a Feature using IFeature Set raster field with IRasterValue Specify storage parameter with IRasterStorageDef void LoadRasterCatalog(IRasterCatalog catalog, IRasterDataset dataset) { IFeatureClass featureclass = (IFeatureClass)catalog; IFeature feature = featureclass.createfeature(); //create raster value and set IRasterValue rastervalue = new RasterValueClass(); rastervalue.rasterdataset = dataset; feature.set_value set_value(catalog.rasterfieldindex, rastervalue); } feature.store Store();

33 Access Raster Dataset in Raster Catalog Open raster catalog Get raster catalog item Get raster dataset IRasterDataset GetRasterCatalogItem(IRasterCatalog catalog, int oid) { IFeatureClass featureclass = (IFeatureClass)catalog; IRasterCatalogItem rastercatalogitem = featureclass.getfeature(oid); } return rastercatalogitem.rasterdataset RasterDataset;

34 Distributed Raster Catalog Loading Designed for an ArcGIS server environment Support parallel loading using available server containers Load a directory or a list of rasters DrLoader IDrLoader IDrLoader : IUnknown InvalidDatasets: String IsBusy: Boolean LastError: IErrorInfo RasterCatalogLoader: IRasterCatalogLoader ServerName: String Cancel GetStats (out pname: String, out pmillis: Double) GetThreadHandle: Long Load (in catalog: String, in Directory: String) LoadDatasets (in catalog: String, in namelist: String)

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